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The Cockroft Equation (Nephron 1976; 16:31)
It is adequate for most adult patients with normal muscle mass and serum creatinine (Scr) < 4.5 mg/dL

CLcr (male) = IBW (140 - Age) / 72Scr)
CLcr (female)= 0.85 IBW (140 - Age)/(72 Scr)
Where: A = age in yrs; IBW = Ideal Body Weight in Kg

The Sanaka equation
(Nephron 1996; 73:137-144 )

For elderly pts (>60) with very low muscle mass and who do not have nephrotic syndrome or severe hepatic disease, the CLcr may be estimated by the Sanaka equation:
CLcr (male) = ABW (19 Alb +32) / 100 Scr
CLcr female)= ABW (13 Alb +29) / 100 Scr
Where: Alb = plasma albumin level (g/dL); Scr = serum creatinine (mg/dL).
ABW = actual body weight in Kg

The metric version of the Sanaka equations:
CLcr (male) = ABW (2 Alb + 35) / 1.24 Scr
CLcr (female) = ABW (Alb + 22) / 0.87 Scr
Where: Alb = plasma albumin level (g/dL);
Scr = serum creatinine (µm/L).
ABW = actual body weight in Kg

Ideal Body Weight
Non-metric Version
IBW (male) = 50 + 2.3 (H - 60)
IBW (fem) = 45.5 + 2.3 (H - 60)
IBW= ideal body weight (Kg);
H = height in inches

The metric version
IBW (male) = 0.9 H - 88
IBW (fem) = 0.9 H - 92
H = height in centimeters.

Dosing Weight = DW = IBW + 0.4 (ABW - IBW)
Where: ABW = actual body wt. in Kg

Jelliffe Equation
Good for adult pts with normal muscle mass and Scr <5 mg/dL.
CLcr (male) = (114 - 0.8A) / Scr
CLcr (female) = 0.9 (114 - 0.8A)/Scr
Where: A = age in yrs; CLcr = creatinine clearance in mL/min/1.73 m²
Note: The pt's BSA must be determined, and the CLcr value obtained by the above equation must be multiplied by (BSA/1.73) to obtain the pt's creatinine clearance in absolute terms (i.e., mL/min).
BSA = Square Root of (Ht x Wt /3600);
Wt = weight in kgs and Ht = height in cm).



Pediatric Patients


I- Traub-Johnson Equation (Am J Hosp Pharm 1980, 37:195). This equation may be used for children 1 - 16 yrs old.
CLcr = 0.28 * H * BSA /Scr
Where: H = height in cm; BSA = body surface area (m²)
BSA = Square Root of (H x W / 3600); (W = weight in kgs and Ht = height in cm)

II- Schwartz Equation (Ped Clinics of America, 1987: 34:571)

CLcr = k*H/Scr


Where: H = height in cm; Scr = serum creatinine concentration (mg/dL); k = propotionality constant whose value depends on several factors as shown below:

Age	k value
low birth weight babies, <1 yr old	0.33
Term (average gestational age) babies, <1 yr old	0.45
Children (1 - 12) and adolescent girls	0.55
Adolescent boys (13 - 17 yrs)	0.70

Clinical Calculators